1. Field of the Invention
This invention pertains to clamping apparatus, and more particularly to apparatus for clamping adjacent sections of tubing or pipe in longitudinal alignment.
2. Description of the Prior Art
It has long been known to clamp fluid carrying tubings and pipes together by means of segmented external clamps. Typically, the ends of each section of pipe are formed with circumferential flanges. The face of each flange is flat for providing intimate sealing contact with the face of the adjacent pipe flange. Gaskets may also be employed to enhance sealing. The side of each flange opposite the flat face is typically tapered divergently toward the flat face. The adjacent pipe sections are held rigidly in proper alignment by a clamp adapted to engage the flanges.
The clamps are usually comprised of at least two pieces pivotable with respect to each other. The clamp pieces are adapted to conform to the tapers of the flanges. In the operative position, the pieces encircle and engage the flanges. Various locking mechanisms are employed to tightly but detachably fasten the free ends of the clamp pieces to each other, thus drawing the two pipe flanges into tight sealing abutting contact. U.S. Pat. Nos. 1,162,362; 2,673,102; and 3,744,825 illustrate pipe clamps having two flange-encircling pieces. U.S. Pat. Nos. 3,181,901 and 4,123,095 disclose three piece clamps. U.S. Pat. No. 2,788,993 shows a four piece clamp.
Flanged pipes and multi-piece pivotable clamps are particularly useful in the food processing industry. That is because the piping system requires frequent disassembly for cleaning, and the flanged connection system allows relatively quick disassembly, cleaning, and assembly.
However, present clamping devices are deficient in important aspects. For example, present clamps allow the hinged pieces to pivot relative to each other through wide angles, sometimes approaching 180.degree.. U.S. Pat. No. 2,788,993 shows an open clamp with the four pivotable pieces lying approximately in a straight line. However, it is clear that the four pieces are not constrained in that configuration. Rather, the pieces are freely swingable so as to be further openable with respect to the closed pipe encircling position. With but one exception, the other patents listed above also are openable more than 90.degree. with respect to the closed position. In U.S. Pat. No. 1,162,362, each of the two clamp pieces is shown opened about 90.degree. with respect to the closed position. However, it appears that the opened position is governed by the relative locations of the pins, not labelled, and the outer diameters of the pieces A. A variation of either component would alter the open position, and it appears that those two variables are not controlled.
The disadvantage of a pipe clamp with widely openable pieces is that the clamp is relatively difficult to manipulate around flanged pipes using only one hand. The normal assembly procedure is to hold adjacent pipes together with one hand and to apply one clamp piece to the flanges with the second hand. However, it is awkward to swing one or more loosely dangling clamp pieces to surround the pipe flanges with one hand while holding two pipes and possibly a gasket together with the other hand.
Accordingly, a need exists for a multipiece flange securing clamp that may be more easily and quickly assembled than is presently possible.